The size of wind turbines for production of power has increased over the years and has reached a size that result in more difficult and complex transportation of the components of the wind turbines, both during transportation of wind turbine components to an installation location, during install of the components and during service on components of the wind turbines.
Especially installation of and service on drive train components of a wind turbine may be inconvenient in that especially drive train components are very heavy, large and thus hard to handle.
U.S. Pat. No. 6,232,673 discloses a wind turbine comprising a drive train module of a wind turbine that by means of a crane can be removed from the of the wind turbine along mounting rails and can be lowered by the crane for repair and maintenance.
EP1991521 discloses a wind turbine with a nacelle comprising an overhead crane for suspending and horizontally moving a dismantled main component of a wind turbine to a lowering position in the nacelle, before lowering the main component towards the ground via an opening in the nacelle.
Both of the above solutions suffers from several disadvantages e.g. in that they are space consuming solutions that requires much space in the nacelle, and that they are systems that are troublesome and time consuming to operate.
WO2009/074859 discloses a wind turbine with guide rails arranged underneath main components in a nacelle of a wind turbine, allowing the components to slide horizontally during disassembly of the components in the wind turbine nacelle. This solution also suffers from several disadvantages, e.g. in that it is a troublesome and time consuming system to operate.
It is thus an object of the invention to overcome the above mentioned drawbacks.